Dilated cardiomyopathy resident survival guide

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Steven Bellm, M.D. [2]

Dilated cardiomyopathy resident survival guide Microchapters
Overview
Causes
Diagnosis
Treatment
Do's
Dont's

Overview

Dilated cardiomyopathy (DCM) relates to a group of heterogeneous myocardial disorders and is characterized by dilatation and impaired contraction and systolic function of the left or both ventricles. Atrial and/or ventricular arrhythmias can occcur, and there is a risk for sudden death. The weight of the heart is increased but the maximal thicknesses of the left ventricular free wall and septum are usually normal as a result of the abnormally dilated chambers.

Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.

• Life-threatening causes:

• Carbon monoxide poisoning

• Common causes:

• Idiopathic
• Myocarditis
• Ischemic heart disease
• Infiltrative disease
• Peripartum cardiomyopathy
• Hypertension
• Human immunodeficiency virus (HIV) infection
• Connective tissue disease
• Substance abuse
• Doxorubicin
• Other

Complete Diagnostic Approach

A complete diagnostic approach should be carried out after a focused initial rapid evaluation is conducted and following initiation of any urgent intervention.

Symptoms of heart failure

History and symptoms: ❑  Hints for etiology (family history, and others) ❑  Duration and onset of illness ❑  Severity and triggers of dyspnea and fatigue, presence of chest pain, exercise capacity, physical activity, sexual activity (NYHA?) ❑  Weight loss/weight gain (cachexia/volume overload?) ❑  Palpitations/(pre)syncope/ICD shocks(adverse prognosis) ❑  Symptoms of transient ischemic attack or thromboembolism (anticoagulation necessary?) ❑  Presence of peripheral edema or ascites (volume overload?) ❑  Problems with breathing at night/ sleep ❑  Medical history: ❑  Prior hospitalizations for HF (adverse prognosis?) ❑  Discontinuation of medications (reasons?) ❑  Medications that may exacerbate HF ❑  Diet (restriction of sodium and fluid intake?)

Physical examination: ❑  Vital signs: ❑  Pulse (strength and regularity?) ❑  Blood pressure (supine and upright) to reflect adequacy of cardiac output ❑  Respiratory rate ❑  General appearance: ❑  BMI(weight loss/weight gain) ❑  Peripheral edema ❑  Heart: ❑  Extra heart sounds and murmurs (S³ associated with adverse prognosis, valvular heart disease?) ❑  Orthostatic changes in blood pressure and heart rate (volume status/vasodilation?) ❑  Jugular venous pressure at rest and following abdominal compression (to identify congestion) ❑  Size and location of point of maximal impulse (ventricular enlargement?) ❑  Right ventricular heave (right ventricular dysfunction and/or pulmonary hypertension?) ❑  Lungs: ❑  Rales ❑  Pleural effusion ❑  Abdomen: ❑  Hepatomegaly and/or ascites (volume overload) ❑  Extremities: ❑  Temperature of lower extremities

Laboratory findings: ❑  Complete blood count ❑  Chemistry: ❑  Troponin, BNP or NT-proBNP ❑  Serum electrolytes (including calcium and magnesium) ❑  Blood urea nitrogen ❑  Serum creatinine ❑  Glucose ❑  Fasting lipid profile ❑  Liver function tests ❑  Thyroid-stimulating hormone ❑  Consider Screening for hemochromatosis, HIV, rheumatologic diseases, amyloidosis, or pheochromocytoma ❑  Urinalysis

Imaging and additional tests: ❑  Noninvasive imaging: ❑  Chest x-ray(heart size, pulmonary congestion and alternative cardiac, pulmonary, and other diseases?) ❑  2-dimensional echocardiogram with Doppler (ventricular function, size, wall thickness, wall motion, and valve function?) ❑  Repeat measurement of EF and severity of structural remodeling (after significant change in clinical status, after clinical event, after treatment or if candidates for device therapy) ❑  Cardiac-MRI (ventricular size, wall/muscle thickness, valves, pericardium, wall motion, etc.) ❑  Consider check for myocardial ischemia and viability for patients with known CAD and no angina ❑  Viability assessment when planning revascularization in HF patients with CAD ❑  Radionuclide ventriculography or magnetic resonance imaging can be useful to assess LVEF and volume when echocardiography is inadequate ❑  Consider magnetic resonance imaging when assessing myocardial infiltrative processes or scar burden

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Treatment

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Do's

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References